Antony's Parthian War

Antony's Parthian War was a major conflict between the Roman Republic and Parthia which occurred between 40 BC and 33 BC in the Levant and Asia Minor regions of western Asia. Antony gathered a massive army of 100,000 soldiers, but his invasion failed due to a lack of strategy, and it would become a strategic draw in 20 BC when the Roman emperor Augustus negotiated peace with Parthia.

Background
In 44 BC, the Roman dictator Julius Caesar planned a campaign against Parthia to avenge the terrible loss at the Battle of Carrhae in 53 BC, planning to pacify Dacia before heading east into Parthia. However, he was assassinated before he could carry out his plans, and the Romans fought each other in a few more civil wars until 42 BC, when the Second Triumvirate emerged victorious over Caesar's killers at the Battle of Philippi. The triumvir Mark Antony was given the eastern provinces of the empire as his third of the Roman Republic's lands, and he cultivated an important alliance with Cleopatra, Queen of Ptolemaic Egypt.

War
In 40 BC, taking advantage of the triumvirs' preoccupation with Sextus Pompeius' Sicilian revolt, King Orodes II of Parthia ordered an invasion of Syria. The Parthian general Barzapharnes invaded Judea, captured Jerusalem, and deposed King Hyrcanus II, replacing him with the puppet ruler Antigonus II Mattathias. In Anatolia, the Parthians allied with the Roman rebel general Quintus Labienus, the son of Titus Labienus, and they defeated and killed the Roman general Lucius Decidius Saxa in Asia Minor.

Mark Antony responded by dispatching a veteran Roman army under Publius Ventidius Bassus to counterattack. Bassus defeated and killed Labienus in battle, and the invaders were driven from Roman territory. In 37 BC, Antony assisted the Jewish prince Herod the Great with capturing Jerusalem and ousting Antigonus from power, ending the Hasmonean dynasty and ushering in the Herodian dynasty. Antony then prepared an army of 100,000 legionaries, aided by the client kings of Armenia, Galatia, Cappadocia, and Pontus, and invaded Media Atropatene. The campaign was disastrous, as Antony failed to capture the Median capital of Phraaspa, and 10,000 of his troops (including Germanic auxiliaries from the Rhineland) were captured, while thousands of Romans and auxiliaries died during the cold winter. Antony eventually lost a quarter of his army, and he used Egyptian money to fund an invasion of Armenia, which had switched sides after a Parthian invasion. Antony succeeded in forcing King Artavasdes II of Armenia to return to his original alliance with Rome, and Antony celebrated a mock triumph in Alexandria. Antony eventually annexed Armenia, afraid that the kingdom would seek Parthian support. The war did not formally end until 20 BC, ten years after Antony and Cleopatra's suicides, when the Roman emperor Augustus secured the release of Roman prisoners and the return of the legionary eagles of Crassus and Saxa's armies.